Search Results

The connecting rods employed in most of general-purpose engines with a power from 1.5 kW to 10 kW are manufactured from aluminum alloy in order to increase productivity and reduce weight, and therefore display lower material strength than steel connecting rods. In terms of operating conditions, general-purpose engines are frequently operated under high load while being held at a comparatively low engine speed, necessitating strength and durability in relation to combustion pressure. Realizing a balance between the rigidity of each part is an important factor in reconciling the achievement of weight reduction in the reciprocating parts while also keeping strength. The research discussed in this paper developed a structure optimization system to examine shape parameters for reciprocating parts targeting 4 kW class engines, and studied shapes that would balance the reduction of weight with the keeping of strength.

This study sought to achieve robust combustion with the differing fuel types and levels of fuel quality that are present in various areas of the world. The tests used the 2-stroke controlled auto ignition (CAI) engine from our earlier report [1], which was proven to have potential as an efficient, clean engine for diesel fuel. This study verified whether efficient, clean CAI combustion of gasoline fuel could be achieved with the same basic structure and engine system. Diesel and gasoline have very different volatility, viscosity and ignition characteristics, all of which significantly affect combustion in an engine. It is particularly necessary in CAI combustion to adjust the ignition timing according to the fuel used, as the difference in auto-ignition temperature from gasoline and diesel affects the CAI ignition timing.